The invention provides a modular assembly which may include integrated circuit devices and photonic devices, and includes a self-contained fluid cooling loop. The module is preferably configured to cooperate with an external chassis or backplane for electrical and photonic integration with other equipment, and to cooperate with external cooling apparatus in the external chassis. The module is especially useful for use with high-powered multi-chip electronic devices that require substantial cooling for proper operation. The working fluid may be a single phase liquid, a single phase vapor or gas, or a two-phase mixed flow medium.
The module typically incorporates a substrate, conventionally designated as a “printed wiring board” (PWB) that provides a base for mounting the components of the module and incorporates appropriate electrical wiring and any optical fiber paths for supplying the active components of the module with power and signals, electrical and optical, through a connector which mates with appropriate interfacial connectors in the mounting chassis.
The base PWB supports an assembly of active devices, such as electronic integrated circuits (ICs), electro-optical devices, and the like, along with appropriate fluid-cooled supporting structures for active devices requiring fluid cooling. The fluid-cooled supporting structures may take the form of one or more interposers containing electrical connections for ICs, and the like, mounted thereon, wherein the interposers incorporate channels through which fluid coolant can be circulated. The active devices mounted on the interposer are typically in thermal (heat transmissive) contact therewith to permit conductive transfer of heat generated within the active devices to the fluid-cooled interposer. In some embodiments of the invention, the active devices may incorporate channels, in fluid-transmissive communication with the channels in the interposer, for circulating cooling fluid through the active devices themselves. The PWB base also supports, or is supported on, a heat exchanger provided with channels for the fluid coolant, which communicate with the channels in the interposer and a small form factor fluid pump to provide a closed cooling loop, through which the coolant is circulated by the pump. The base PWB may also support other electronic or electro-optical devices, or the like, which do not require fluid cooling.
The heat exchanger can be configured to cooperate with cooling apparatus in the mounting chassis, into which the module of the invention is designed to be fitted or plugged, in order to dispose of heat extracted from the devices mounted in the module by transferring the heat to the external environment.
The external chassis that receives the module of the invention as a plug-in component may be any conventional equipment mounting chassis capable of providing the electrical, optical (if necessary), and thermal interfaces required to connect the module for cooperation with external apparatus. Such equipment mounting chassis are conventional in both fixed installations and mobile equipment, such as land vehicles, ships, aircraft, spacecraft, and the like.
The heat exchanger component of the module, in addition to the channels for circulating coolant, may also incorporate channels, fins, or the like, for heat transfer to a stream of cooling air provided by external equipment, e.g., by the mounting chassis. Alternatively, the heat exchanger component of the module may transfer heat to the next higher assembly by means of a conductive heat transfer interface.
In various embodiments of the module, multiple dies (or “chips”) from any variety of commercial and/or military suppliers are mounted to an interposer comprising power, signal (electrical or photonic), and cooling interfaces. The “chips” technology suitable for incorporation in the fluid-cooled modules of the invention may include processors, graphics processors, digital signal processors (DSP), radio-frequency integrated circuits (RFIC), power amplifiers, and the like. The interposer and chips may also be contained within a volume protection technology which is in turn mounted to a printed wiring board with surface mount technology. The PWB may in turn be fixed to a heat exchanger incorporating channels or conduits for the cooling fluid. Fluid is exchanged between the interposer and the heat exchanger by means of a small pump integrated into the module. In one of numerous variations, a fluid-to-air heat exchanger is combined with the fluid-channel heat exchanger by incorporating an air-cooled heat exchanger therein. In certain embodiments of the invention, the heat exchanger may be fixed directly to an interposer, rather than to the base PWB. In certain embodiments of the invention, the heat exchanger may be incorporated within a lid or cover for a component of the module (e.g., a lower level assembly of the module such as a ball grid array (BGA) hybrid), rather than to the base PWB.
Accordingly, in one of its principal aspects, the present invention provides an electric or electro-optical module, comprising:
an electronic or electro-optical component mounted on an interposer; and
a closed-loop fluid cooling path providing fluid communication to the heat exchanger from the interposer.
According to another of its principal the invention comprises a fluid-cooled electronic or electro-optical module, comprising:
an interposer having at least electrical circuitry and having at least one cooling fluid channel;
a micro-electronic or electro-optical device mounted on said interposer in heat transmissive contact therewith;
a heat exchanger; and
a closed-loop fluid cooling path providing fluid communication exclusively between the heat exchanger and the interposer.
According to another of its principal aspects, the present invention provides an electric or electro-optical module, comprising:
an electronic or electro-optical component mounted on an interposer;
a closed-loop fluid cooling path providing fluid communication to a heat exchanger from the interposer;
a printed wiring board;
the interposer mounted on the printed wiring board;
the printed wiring board being mounted to the heat exchanger; and
a pump mounted on the printed wiring board or the interposer in the fluid cooling path to circulate the fluid through the interposer and the heat exchanger.
The invention permits operation of electronic and electro-optical devices at substantially higher power densities as compared with modules provided only with convective cooling, forced air cooling, or the like. Thus, a typical module of the invention having a size of about 6 inches×4 inches×1 or 2 inches, can be capable of supporting devices having a total heat dissipation on the order of 300 to 500 watts, depending on heat rejection limitations of associated chassis equipment.